Study of firefighters finds potential pathway between insomnia and depression

DARIEN, IL – A new study of firefighters suggests that insomnia and nightmares may increase the risk of depression by impairing the ability to access and leverage emotion regulation strategies effectively.

Results show that a high percentage of participants reported clinically significant insomnia symptoms (52.7 percent), depression symptoms (39.6 percent) and nightmare problems (19.2 percent). Further analyses revealed that the indirect effects of overall emotion regulation difficulties were significant both for the relationship between insomnia and depression and nightmares and depression. Limited access to emotion regulation strategies – such as problem-solving skills and the ability to decrease negative emotions – emerged as the strongest, most significant indirect effect for both relationships.

"Our study findings suggest that firefighters with sleep difficulties are likely to experience greater struggles accessing strategies to regulate their emotions, especially when feeling upset. This, in turn, may lead to or worsen feelings of depression and low mood," said lead author Melanie Hom, a doctoral candidate in the Laboratory for the Study and Prevention of Suicide-Related Conditions and Behaviors within the department of psychology at Florida State University in Tallahassee, Florida. "These results are important because they provide a plausible explanation for why and how sleep problems may contribute to depression, which are critical questions for prevention and intervention."

Study results are published in the February 15 issue of the Journal of Clinical Sleep Medicine.

According to the American Academy of Sleep Medicine, transient insomnia symptoms occur in 30 to 35 percent of the population. Chronic insomnia, which occurs at least three times per week for at least three months, affects about 10 percent of adults. Approximately 2 to 8 percent of the general population has a current problem with nightmares, and trauma-related nightmares are the most consistent problem reported by people who have post-traumatic stress disorder.

Led by Hom and under the supervision of Dr. Thomas Joiner, the research team analyzed responses from 880 current and retired United States firefighters between the ages of 18 and 82 years. Participants completed a web-based survey of behavioral health. Self-report measures included the Center for Epidemiologic Studies Depression Scale, Insomnia Severity Index, PTSD Checklist, and Difficulties in Emotion Regulation Scale.

"Firefighters are typically faced with many demands, including difficult work schedules, and they often both witness and experience traumatic events," said Hom. "It is not surprising that firefighters may experience sleep problems and depression, but it is critical that greater efforts be made to prevent and treat these problems."

According to the authors, the findings suggest that emotion dysregulation may be an important therapeutic target for reducing depression risk among firefighters and other individuals who experience insomnia and nightmares.

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The study was supported by grants from the National Fallen Firefighters Foundation; National Institutes of Health; and Military Suicide Research Consortium, an effort supported by the Office of the Assistant Secretary of Defense for Health Affairs.

To request a copy of the study, "The Association between Sleep Disturbances and Depression among Firefighters: Emotion Dysregulation as an Explanatory Factor," or to arrange an interview with the study author or an AASM spokesperson, please contact Communications Coordinator Lynn Celmer at 630-737-9700, ext. 9364, or [email protected]

The monthly, peer-reviewed Journal of Clinical Sleep Medicine is the official publication of the American Academy of Sleep Medicine, a professional membership society that improves sleep health and promotes high quality patient centered care through advocacy, education, strategic research, and practice standards (http://www.aasmnet.org). The AASM encourages patients to talk to their doctor about sleep problems and visit http://www.sleepeducation.org for more information about sleep and a searchable directory of AASM accredited sleep centers.